The growing digitization of power grids has increased their vulnerability to cyberattacks, potentially leading to widespread power outages. While many studies address cyber-induced outages, resulting cascading failures are often overlooked. This paper introduces a planning framework that employs cyber-physical measures to mitigate these disruptions. It generates a range of cyberattack scenarios, including denial of service (DoS) attack and load alter attacks (LAA) on substations while accounting for uncertainties. These cyberattacks can shift the grid's stable operating point, potentially triggering protection mechanisms and causing cascading failures. The impact of these failures is quantified using a cascading failure model that quantifies the demand not served. The framework integrates cyber-physical measures, including the optimal allocation of cyber reinforcement units (which may include components like phasor measurement units and other cyber-defense mechanisms) and energy storage systems to reduce cascading propagation. The framework's effectiveness in reducing cascading impacts is evaluated using the IEEE 39-bus system.